"Neural Dust": A New Approach to Brain Machine Interfaces
University of California Berkeley scientists have proposed a system that allows for thousands of ultra-tiny “neural dust” chips to be inserted into the brain to monitor neural signals at high resolution and communicate data highly efficiently via ultrasound.
…The neural dust system has three basic elements:
- Thousands of low-power CMOS chips… embedded into the cortex between neurons [that] detect extracellular electrophysiological signals via an electrode and convert the signals into ultrasonic signals using a piezoelectric sensor
- A subdural (the dura surrounds the brain and keeps in the cerebrospinal fluid) ultrasonic transceiver (transmitter receiver) receives ultrasonic signals from the neural dust [and] powers the neural dust with ultrasonic energy.
- A battery-powered external transceiver communicates via ultrasound with the subdural transceiver and transmits the data to an external computer.
Embedded ~2 mm. in the brain, the powered neural dust chips can be as small as tens of microns (millionths of a meter). Ultrasound is attractive for in-tissue communication given its short wavelength and low attenuation.
The design also uses more efficient “backscatting”: instead of transmitting energy, the chips passively modulate ultrasonic energy from the sub-dural transceiver and reflect it back.
The researchers calculate that the neural dust chips can be as much as 10 million times more efficient that chips using electromagnetics (magnetic or electric signals), which have high attenuation in brain tissue. They would be encapsulated in an inert polymer or insulator ﬁlm.
(via ‘Neural dust’ brain implants could revolutionize brain-machine interfaces and allow large-scale data recording | KurzweilAI)